- Mild and Regioselective Bromination of Phenols with TMSBr
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In this work, an unexpected promoting effect of by-product thioether was observed, leading to a mild and regioselective bromination of phenols with TMSBr. This method can tolerate a series of functional groups such as the reactive methoxyl, amide, fluoro, chloro, bromo, aldehyde, ketone and ester groups, and has the potential to recycle the by-product thioether and isolate the desired product under column chromatography-free conditions. Mechanism studies revealed that O–H···S hydrogen bond may be formed between phenol and by-product thioether. Possibly owing to the steric hindrance effect from by-product thioether, the electrophilic bromination at para-position of phenols is much favorable.
- Ma, Xiantao,Yu, Jing,Jiang, Mengyuan,Wang, Mengyu,Tang, Lin,Wei, Mengmeng,Zhou, Qiuju
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supporting information
p. 4593 - 4596
(2019/07/05)
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- A phenol compound high regioselective bromination method
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The invention discloses a phenol compound high regioselective bromination of the method, the method to trimethyl silane as brominating agent, in order to aryl sulfoxide as activator, with the phenol compound in the 0 - 50 °C lower, in a solvent, the reaction is stirred under an atmosphere of nitrogen at 1 - 12 hours, to realize the phenol compound high regioselective bromination, filtered, extraction columns chromatography separation to obtain the bromo phenol compound. This invention adopts the aryl sulfoxide as activator, sulfoxide substituted Kiev, on the one hand so that the phenol compound bromo the higher selectivity of the reaction region, and when the phenol compound hydroxy alignment not substituted basetime, regional selective para - bromo product, when the phenol compound hydroxy position there is substituted basetime, selective ortho - bromo product obtained; on the other hand if it through the filter, the extraction can be realized at the same time the isolation and purification of the recycling of the by-product, compared with column chromatography, reduces the separation and purification cost.
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Paragraph 0040; 0041; 0042
(2019/06/05)
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- INHIBITORS OF CBL-B AND METHODS OF USE THEREOF
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Compounds, compositions, and methods for use in inhibiting the E3 enzyme Cbl-b in the ubiquitin proteasome pathway are disclosed. The compounds, compositions, and methods can be used to modulate the immune system, to treat diseases amenable to immune system modulation, and for treatment of cells in vivo, in vitro, or ex vivo.
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Paragraph 1386
(2019/08/12)
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- Method for preparing pranlukast key intermediate 3-amino-2-hydroxyacetophenone
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The invention provides a method for preparing a pranlukast key intermediate 3-amino-2-hydroxyacetophenone. The method takes 2-aminophenol as an initial raw material, 2-aminophenol and acetic anhydride are subjected to a synthesis reaction in water to obtain 2-acetaminophenol, then 2-acetamido-4-bromophenol is prepared by 2-ace-taminophenol and NBS under room temperature, 2-hydroxy-3-amino-5-bromoacetophenone is prepared by a Hoesch reaction, finally 2-hydroxy-3-amino-5-bromoacetophenone is dissolved in ethanol, and a Pd/C is added for catalytic hydrogenation and bromine removal to obtain the 3-amino-2-hydroxyacetophenone. The raw materials have the advantages of low cost, easy acquisition, diversified raw material selection, easy realization of production technology, and easy control, the purity of the final product is high, no dangerous process is generated, the equipment is simple, the synthesis route is novel, the synthesis route is short, the production power is increased, and production processing cost is reduced.
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- Cp?Rh(III)/Bicyclic Olefin Cocatalyzed C-H Bond Amidation by Intramolecular Amide Transfer
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A bicyclic olefin was discovered as a cocatalyst in a Cp?Rh(III)-catalyzed C-H bond amidation proceeding by an intramolecular amide transfer in N-phenoxyacetamide derivatives. Combining experimental and theoretical studies, we propose that the olefin promotes a Rh(III) intermediate to undergo oxidative addition into the O-N bond to form a Rh(V) nitrenoid species and subsequently direct the nitrenoid to add to the ortho position. The amide directing group plays a dual role as a cleavable coordinating moiety as well as an essential coupling partner for the C-H amidation. This methodology was successfully applied to the late-stage diversification of natural products and a marketed drug under mild conditions.
- Wang, Xiaoming,Gensch, Tobias,Lerchen, Andreas,Daniliuc, Constantin G.,Glorius, Frank
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p. 6506 - 6512
(2017/05/17)
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- Synthesis of benzoxazoles from 2-aminophenols and β-diketones using a combined catalyst of br?nsted acid and copper iodide
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Cyclization reactions of 2-aminophenols with β-diketones catalyzed by a combination of Br?nsted acid and CuI are presented. Various 2-substituted benzoxazoles were obtained through these reactions. Different substituents such as methyl, chloro, bromo, nitro, and methoxy on 2-aminophenol are tolerated under the optimized reaction conditions.
- Mayo, Muhammad Shareef,Yu, Xiaoqiang,Zhou, Xiaoyu,Feng, Xiujuan,Yamamoto, Yoshinori,Bao, Ming
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p. 6310 - 6314
(2014/07/21)
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- Identification and development of an efficient route to SB-649915
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The discovery and development of an efficient manufacturing route to the SSRI-5-HT1A receptor antagonist 6-[(1-{2-[(2-methyl-5-quinolinyl)oxy]ethyl}-4- piperidinyl)methyl]-2H-1,4-benzoxazin-3(4H)-one (SB-649915) 1 is described. The existing route to 1 involved coupling quinoline 6 with piperidine 5 and was considered lengthy as a consequence of the nine synthetic steps required to prepare 5. Two new routes to the key piperidine intermediate 5 are identified which deliver this compound in five and two steps respectively, from readily available materials using novel lithiation and Friedel-Crafts methodology respectively. The latter of these two routes was successfully demonstrated at 5 L scale to deliver 700 g of 5. Development to the methanesulfonate 34, an alternative to quinoline 6, is also described as is the final alkylation of piperidine 5 with this methanesulfonate 34 to deliver SB-649915 1.
- Armitage, Mark,Bret, Guillaume,Choudary, Bernie M.,Kingswood, Mike,Loft, Mike,Moore, Steve,Smith, Steve,Urquhart, Michael W. J.
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p. 1626 - 1634
(2013/02/22)
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- 1,2,4-TRIAZINE-4-AMINE DERIVATIVES
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According to the invention there is provided a compound of formula A1 which may be useful in the treatment of a condition or disorder ameliorated by the inhibition of the A1- A2b or, particularly, the A2a receptor wherein the compound of formula A1 has the structure, wherein, A represents Cy1 or HetA; Cy1 represents a 5- to 14-membered aromatic, fully saturated or partially unsaturated carbocyclic ring system comprising one, two or three rings, which Cy1 group is optionally substituted by one or more R4a substituents; HetA represents a 5- to 14-membered heterocyclic group that may be aromatic, fully saturated or partially unsaturated, and which contains one or more heteroatoms selected from O, S and N, which heterocyclic group may comprise one, two or three rings and which HetA group is optionally substituted by one or more R4b substituents; B represents a Cy2 or HetB; Cy2 represents a 3- to 10-membered aromatic, fully saturated or partially unsaturated carbocyclic ring system comprising one or two rings, which Cy2 group is optionally substituted by one or more R4c substituents; HetB represents a 3- to 10-membered heterocyclic group that may be aromatic, fully saturated or partially unsaturated, and which contains one or more heteroatoms selected from O, S and N, which heterocyclic group may comprise one or two rings and which HetB group is optionally substituted by one or more R4d substituents.
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Page/Page column 201-202
(2011/09/14)
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- Improved P1/P1' substituents for cyclic urea based HIV-1 protease inhibitors: Synthesis, structure-activity relationship, and X-ray crystal structure analysis
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We present several novel P1/P1' substituents that can replace the characteristic benzyl P1/P1' moiety of the cyclic urea based HIV protease inhibitor series. These substituents typically provide 5-10-fold improvements in binding affinity compared to the unsubstituted benzyl analogs. The best substituent was the 3,4-(ethylenedioxy)benzyl group. Proper balancing of the molecule's lipophilicity facilitated the transfer of this improved binding affinity into a superior cellular antiviral activity profile. Several analogs were evaluated further for protein binding and resistance liabilities. Compound 18 (IC90 = 8.7 nM) was chosen for oral bioavailability studies based on its log P and solubility profile. A 10 mg/kg dose in dogs provided modest bioavailability with C(max) = 0.22 μg/mL. X-ray crystallographic analysis of two analogs revealed several interesting features responsible for the 3,4-(ethylenedioxy)benzyl-substituted analog's potency: (1) Comparing the two complexes revealed two distinct binding modes for each P1/P1' substituent; (2) The ethylenedioxy moieties are within 3.6 A? of Pro 81 providing additional van der Waals contacts missing from the parent structure; (3) The enzyme's Arg 8 side chain moves away from the P1 substituent to accommodate the increased steric volume while maintaining a favorable hydrogen bond distance between the para oxygen substituent and the guanidine NH.
- Nugiel, David A.,Jacobs, Kim,Cornelius, Lyndon,Chang, Chong-Hwan,Jadhav, Prabhakar K.,Holler, Edward R.,Klabe, Ronald M.,Bacheler, Lee T.,Cordova, Beverly,Garber, Sena,Reid, Carol,Logue, Kelly A.,Gorey-Feret, Lorraine J.,Lam, Gilbert N.,Erickson-Viitanen, Susan,Seitz, Steven P.
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p. 1465 - 1474
(2007/10/03)
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- Halogenation Using Quaternary Ammonium Polyhalides. XI. Bromination of Acetanilides by Use of Tetraalkylammonium Polyhalides
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The reaction of acetanilides with tetraalkylammonium polyhalides, such as tetrabutylammonium tribromide, benzyltrimethylammonium tribromide, and benzyltrimethylammonium chlorobromate(1-), in dichloromethane-methanol at room temperature gave bromosubstituted acetanilides in good yields, respectively.
- Kajigaeshi, Shoji,Kakinami, Takaaki,Yamasaki, Hiromichi,Fujisaki, Shizuo,Okamoto, Tsuyoshi
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p. 2681 - 2683
(2007/10/02)
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